RESUMO
In vivo expression of CO dehydrogenase/acetyl coenzyme A synthase in Methanosarcina spp. is coordinately regulated in response to substrate by at least two mechanisms: differential transcription initiation and early elongation termination near the 3' end of a 371-bp leader sequence. This is the first report of regulation of transcription elongation in the Archaea.
Assuntos
Aldeído Oxirredutases/fisiologia , Methanosarcina/enzimologia , Methanosarcina/genética , Complexos Multienzimáticos/fisiologia , Regiões 5' não Traduzidas/genética , Regiões 5' não Traduzidas/fisiologia , Aldeído Oxirredutases/genética , Proteínas Arqueais/genética , Proteínas Arqueais/fisiologia , Sequência de Bases , Regulação da Expressão Gênica em Archaea/genética , Dados de Sequência Molecular , Complexos Multienzimáticos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica/genéticaRESUMO
A recombinant protein overproduction system was developed in Methanosarcina acetivorans to facilitate biochemical characterization of oxygen-sensitive metalloenzymes from strictly anaerobic species in the Archaea domain. The system was used to overproduce the archetype of the independently evolved gamma-class carbonic anhydrase. The overproduced enzyme was oxygen sensitive and had full incorporation of iron instead of zinc observed when overproduced in Escherichia coli. This, the first report of in vivo iron incorporation for any carbonic anhydrase, supports the need to reevaluate the role of iron in all classes of carbonic anhydrases derived from anaerobic environments.
